Deflector for controlling entry of cooling air leakage into the gaspath of a gas turbine engine

Abstract

A deflector for redirecting cooling air leakage to improve the efficiency of a gas turbine engine rotors. Adjacent rotor blades have a radially extending gap between each adjacent rotor blade and cooling air leaks into the gaps resulting in engine inefficiency. A deflector, disposed circumferentially on a forward face of the coverplate, deflects cooling air leakage, flowing from the running seal through the cooling air leakage path, away from the gaps between the blades, onto the outward surface of the blade platform, and into the gaspath at an acute angle relative to rearwardly axial flow. A forwardly extending flange deflects cooling air leakage forwardly around the blade platform lip.

What is claimed is: 
     
       1. In a gas turbine engine including a forward stator assembly and a rotor assembly having: an air cooled rotor disc with an axis, a forward radially outward edge, and a circumferential array of blade retention slots;   a plurality of air cooled rotor blades with blade bases retained in each one of said slots, the rotor blades having blade platforms and blade airfoils radially extending outboard of the disc into a hot annular gaspath, the rotor blades disposed equidistantly about the circumference of the rotor disc with a radially extending gap between each adjacent rotor blade;   a circular coverplate having: an annular disc sealing edge engaging the rotor disc and blade bases radially inward of the disc forward edge; and an annular stator sealing edge forming running seal means with the stator assembly for separating cooling air from the hot gaspath;   a cooling air leakage path from the running seal means to the gaspath being defined between the stator assembly, coverplate, rotor disc and rotor blades;   wherein the improvement comprises: cooling air leakage deflection means extending circumferentially from the coverplate, for deflecting cooling air leakage, flowing from the running seal through the cooling air leakage path, away from the gaps between the blades and for deflecting cooling air leakage forwardly around the blade platform lip, onto an outward surface of the blade platform, and into the gaspath at an acute angle relative to rearwardly axial flow therein, wherein the cooling air leakage deflection means comprise a forwardly extending deflector flange contiguous with the disc sealing edge of the coverplate.     
     
     
       2. A deflector according to claim 1 comprising a nickel alloy. 
     
     
       3. A deflector according to claim 2 comprising waspalloy. 
     
     
       4. A deflector according to claim 1 further comprising a deflector base extending radially inwardly from the deflector flange, the defector base adapted for overlapping clamping engagement between the rotor disc and the disc sealing edge of the coverplate. 
     
     
       5. A deflector according to claim 4 wherein the flange is tapered with decreasing thickness forwardly. 
     
     
       6. A deflector according to claim 4 wherein the flange at rest is disposed at a distance radially inward from an underside surface of the blade platforms.